Final Report Summary - SELFCOMPLETION (UV-Completion through Bose-Einstein Condensation: A Quantum Model of Black Holes)
One of the main goals of the fundamental physics is to understand nature
at various length-scales. When moving from longer distances to
shorter ones the effective description changes accordingly:
A macroscopic theory applicable at large distances must be replaced
by a more powerful microscopic theory valid at shorter length-scales.
This process is called an ultra-violet(UV)-completion of the theory. In the conventional approach which we refer to as Wilsonian the UV-completion process necessarily requires an introduction of new high-energy elementary particle degrees of freedom that were not present in the low energy theory.
The idea of Self-Completion that was put forward by the PI-s of the project
and to which the project is devoted offers an alternative possibility.
Namely, the certain theories UV-complete themselves without the
need of new microscopic elementary particle degrees of freedom. Instead, they incorporate the collective multi-particle excitations of the ``old" low energy degrees of freedom. Such multi-particle excitations behave approximately classically and therefore the process was referred to as
Classicalization.
The main candidate theory for self-completion is gravity which includes the excellent tools for classicalization in form of black holes.
The complete understanding of self-completion therefore requires the understanding of the microscopic structure of a black hole and
of the processes in which black holes are produced in collisions of very high
energy quantum particles. Higher is the energy in the collision, bigger and thus more classical is the resulting black hole. In this way the idea of self-completion intrinsically links the consistency of quantum gravitational interaction at very high energies with the properties of very large black holes.
From the idea of self-completion by Classicalization is follows that a large black hole represents a state of soft gravitons of very high occupation number. Such a system is at a very special critical point where the quantum interaction strength of soft gravitons (which is minuscule) is exactly compensated by their enormously high occupation number.
Thus, this picture naturally links black holes with other systems
with high occupation number of bosons such as the Bose-Einstein condensates. In this way the key to the understanding of the mysterious quantum properties of black holes, such as their maximal micro-state entropy and quantum information processing, is encoded in their multi-particle nature.
By approaching the problem from various angles ranging from computations of multi-graviton scattering amplitudes to the analysis of prototype many-body models, we gathered a strong evidence supporting the above view.
Our studies uncovered some qualitatively new phenomena such as the phenomenon of ``Quantum-Breaking" and the effect of ``Memory Burden".
These effects are predicted to be the universal properties of the systems with enhanced memory storage capacity such as black holes or attractive Bose-Einstein condensates near criticality. This result is interesting in two ways.
First it predicts the new phenomenon in black hole physics. Namely that after their half-life time the black holes undergo the effect of quantum-breaking beyond which the classical description is no longer available and Hawking radiation is no longer thermal. This is highly unexpected since at this stage the occupation number is still huge and by all counts the black hole is macroscopic! What happens after this stage requires a further study.
Secondly, the underlying connection with Bose-Einstein condensate opens up an exciting prospect in simulating black hole information processing and quantum computing in table top lab experiments with cold bosons.
at various length-scales. When moving from longer distances to
shorter ones the effective description changes accordingly:
A macroscopic theory applicable at large distances must be replaced
by a more powerful microscopic theory valid at shorter length-scales.
This process is called an ultra-violet(UV)-completion of the theory. In the conventional approach which we refer to as Wilsonian the UV-completion process necessarily requires an introduction of new high-energy elementary particle degrees of freedom that were not present in the low energy theory.
The idea of Self-Completion that was put forward by the PI-s of the project
and to which the project is devoted offers an alternative possibility.
Namely, the certain theories UV-complete themselves without the
need of new microscopic elementary particle degrees of freedom. Instead, they incorporate the collective multi-particle excitations of the ``old" low energy degrees of freedom. Such multi-particle excitations behave approximately classically and therefore the process was referred to as
Classicalization.
The main candidate theory for self-completion is gravity which includes the excellent tools for classicalization in form of black holes.
The complete understanding of self-completion therefore requires the understanding of the microscopic structure of a black hole and
of the processes in which black holes are produced in collisions of very high
energy quantum particles. Higher is the energy in the collision, bigger and thus more classical is the resulting black hole. In this way the idea of self-completion intrinsically links the consistency of quantum gravitational interaction at very high energies with the properties of very large black holes.
From the idea of self-completion by Classicalization is follows that a large black hole represents a state of soft gravitons of very high occupation number. Such a system is at a very special critical point where the quantum interaction strength of soft gravitons (which is minuscule) is exactly compensated by their enormously high occupation number.
Thus, this picture naturally links black holes with other systems
with high occupation number of bosons such as the Bose-Einstein condensates. In this way the key to the understanding of the mysterious quantum properties of black holes, such as their maximal micro-state entropy and quantum information processing, is encoded in their multi-particle nature.
By approaching the problem from various angles ranging from computations of multi-graviton scattering amplitudes to the analysis of prototype many-body models, we gathered a strong evidence supporting the above view.
Our studies uncovered some qualitatively new phenomena such as the phenomenon of ``Quantum-Breaking" and the effect of ``Memory Burden".
These effects are predicted to be the universal properties of the systems with enhanced memory storage capacity such as black holes or attractive Bose-Einstein condensates near criticality. This result is interesting in two ways.
First it predicts the new phenomenon in black hole physics. Namely that after their half-life time the black holes undergo the effect of quantum-breaking beyond which the classical description is no longer available and Hawking radiation is no longer thermal. This is highly unexpected since at this stage the occupation number is still huge and by all counts the black hole is macroscopic! What happens after this stage requires a further study.
Secondly, the underlying connection with Bose-Einstein condensate opens up an exciting prospect in simulating black hole information processing and quantum computing in table top lab experiments with cold bosons.